This thread is resolved. Here is a description of the problem and solution.
Problem:
You are trying to translate a string in the WooCommerce Product Addon plugin using WPML, but WPML does not detect the translatable string 'validate_msg' => __( 'is a required field', 'woocommerce-product-addon').
Solution:
We recommend enabling the "Auto-register strings" option in WPML. After enabling, visit the page that contains this string on the front end. Then, search for the string in the WPML String Translation.
If this solution does not resolve your issue, or if it seems outdated or irrelevant to your case, please check the related known issues and verify that you have installed the latest versions of themes and plugins. If the problem persists, we highly recommend opening a new support ticket at WPML support forum for further assistance.
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